Reality Needles Cheadle
In the film Hotel Rwanda, Don Cheadle plays Paul Rusesabagina, the Rwandan hotelier who used his resort in Kigali city as a safe haven during the African nation's 1994 civil war. It was a tough role to tackle, made even tougher by the presence of the real-life Rusesabagina on the set. "It's daunting when [Paul] is sitting behind the monitor as you're doing a scene," says Cheadle, 40. "You obsess over every single detail. You're looking at his face, trying to interpret if that's a frown, a grimace or a smile. Finally I said, 'Just get him out of here. Take him to the lunch trailer, get him a sandwich and let me do this scene!' "

Bacon's Balancing Act
Though Kevin Bacon plays a pedophile in the controversial drama The Woodsman, he found that acting alongside his wife of 16 years, Kyra Sedgwick, was even more challenging. "It's great that there is a fantastic actress when you get to the set and it's someone you trust. But in terms of a marriage, it's not the best thing," says Bacon, 46. "What we found is that she works and I become her support system; then I work and she becomes my support system. When we're both working on the same project, it's hard for us to be there for each other as husband and wife. We sort of come back together after the job is over."

The Phantom Menace
Scottish actor Gerard Butler doesn't mask his frustration with playing the title role in The Phantom of the Opera. "The hours of prosthetic makeup I had would psychologically screw me up. Gluing my eye was torture," says Butler, 35. "By the time they finished, you're ready to bite somebody's head off." The double-stick tape used on his mask was no party either. "The tape would stick so tightly to my face that I couldn't move. I'd be pulling my skin off and it would bruise. [And when I went] down in the Phantom's lair where it was really hot, the mask wouldn't stay on. I'd be performing and the eye hole would be down to my cheek. It was a comedy routine."

Samuel's On-Set Antics
To play the head of a high school basketball team in the new drama Coach Carter, Samuel L Jackson worked with a younger, less experienced cast. "I had no chemistry with those guys. They're just starting their careers. I hate young people; they have no skills," jokes the actor, 56. "They were trying to make stuff up. I was like, 'Hey, you can't make up stuff if I have to say a line after you. I have to know what you're going to say. Get it right!' " Not that Jackson was a mature role model on the set. "I did things to make them laugh when they had to be serious," he says. "All you have to do is cross your eyes and they can't keep it together. They were so easy to crack."

Hayden's Harsh Treatment
Hell hath no fury like a zebra scorned-just ask Racing Stripes' Hayden Panettiere, who stars in the action film. "They kick and bite. I'd run in the opposite direction," says the actress, 15, who plays a teen training a baby zebra to become a racehorse. "We had two zebras: Zoey and Columbia. I was supposed to bond with them. But Zoey would run between us to keep me as far away as possible. But she learned to love me."